[A case of initially unresectable pancreatic cancer with arterial invasion successfully resected after chemotherapy].

A 63-year-old man was diagnosed with pancreatic head cancer, and an operation was planned at his previous hospital. However, resection was not possible because of invasion of the superior mesenteric artery, and gemcitabine-based chemotherapy was administered for the tumor for 2 years. Imaging examinations after chemotherapy were unable to detect the tumor at the pancreatic head or the arterial invasion. The patient was subsequently referred to our hospital for surgery. Upon laparotomy, the tumor was judged to be resectable, and a pancreaticoduodenectomy was performed. Pathological examination indicated the presence of cancer cells in the resected specimens. The patient underwent adjuvant chemotherapy and is currently alive without recurrence. This case highlights the importance of ongoing follow-up in patients with locally advanced pancreatic cancer so that tumor resectability can be evaluated during chemotherapy.